<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>9.常见的无意义标签</title>
</head>
<body>
    <!--
        div     占用整行
        span    不占用整行，长度取决于内部元素的长度
    -->
    <div>div标签</div>
    <div>div标签</div>
    <span>span标签</span>
    <span>span标签</span>
</body>
</html>